Three months after hackers working for a cyberunit of China’s People’s Liberation Army went silent amid evidence that they had stolen data from scores of American companies and government agencies, they appear to have resumed their attacks  using different techniques, according to computer industry security experts and American officials.

The Obama administration had bet that “naming and shaming” the groups, first in industry reports and then in the Pentagon’s own detailed survey of Chinese military capabilities, might prompt China’s new leadership to crack down on the military’s highly organized team of hackers — or at least urge them to become more subtle.

But Unit 61398, whose well-guarded 12-story white headquarters on the edges of Shanghai became the symbol of Chinese cyberpower, is back in business, according to American officials and security companies.

MORE:   Chinese Hackers Resume Attacks on U.S. Targets – NYTimes.com.